An in-depth exploration of the spatial patterns and drivers of plant and soil stoichiometry is important for grasping elemental cycling and quantifying ecosystem responses to environmental factors. This paper experimentally determined the carbon (C), nitrogen (N) and phosphorus (P) contents of Qinghai spruce tissues and soils at different latitudes on the northern slopes of the Qilian Mountains. One-way ANOVA, Pearson correlation, and redundancy analysis were used to reveal the stoichiometric characteristics and key influencing factors of Qinghai spruce and understorey soils at different latitudes on the northern slopes of the Qilian Mountains. The results showed that: (1) the C and N contents of the Qinghai spruce tissues and soils decreased with the increasing latitude; whereas the N:P and C:P of the Qinghai spruce tissues increased with the increasing latitude, and the N:P and C:P of the soils decreased. (2) The nutrient distribution of Qinghai spruce tissues was unbalanced, with the content of C and N elements in the order of leaves>branches>roots, and the content of P elements in the order of branches>leaves>roots, and the N:P of Qinghai spruce branches and roots being less than 14, which indicated that the growth of Qinghai spruce in Qilian Mountains was limited by soil N element. (3) Changes in soil factors (water content, pH, bulk weight, SOC, TN, TP and SOC:TN:TP) and climatic factors (mean annual temperature and mean annual precipitation) affected the elemental content of N and P in Qinghai spruce tissues. The soil factors explained more of the N, P, and N:P of plant tissues than did the climatic factors, in which, the plant leaf N and N:P were positively correlated with soil TN and TN:TP ( P<0.05), while plant root N, N:P values were negatively correlated with temperature and significantly positively correlated with mean annual precipitation (P<0.05). The study helps to assess the plant-soil nutrient dynamics of Qinghai spruce ecosystems in the Qilian Mountains, and explore the mechanism of nutrient regulation and allocation in Qinghai spruce forests at different latitudes, with a view to providing a scientific basis for the sustained and healthy development of forest ecosystems in the Qilian Mountains.